The invention relates to a communication system in which multiple signals, on multiple optical waveguides, arrive at a switch. The switch converts the optical signals into electronic signals and routes each electronic signal to a selected transmitter, which generates optical signals for transmission onto an output waveguide. However, in these processes, the invention performs no local recovery of a clock signal from the incoming signals.
In optical communication, a component called a xe2x80x9cswitchxe2x80x9d is used. The switch performs a routing function. A given switch may receive signals from ten input optical fibers. That switch may connect to ten outgoing optical fibers.
The switch routes signals from each input fiber to a selected output fiber. For example, at a given point in time, the routing may be as shown in the following Routing Table.
The Table shows that input fiber number 1 is connected to output fiber number 10, input 2 is connected to output 9, and so on.
The signals carried by all fibers, input and output, are asynchronous: no clock signal accompanies them. For reasons which need not be explained here, the switch xe2x80x9crecoversxe2x80x9d a clock signal from the incoming signal on a fiber, and utilizes that recovered clock signal for its own internal purposes.
The circuitry involved in recovering the clock signal consumes large amounts of area within an integrated circuit, and also consumes large amounts of power.
In one form of the invention, a switch accepts multiple input signals on multiple optical waveguides, and routes each signal to an output waveguide, but without recovering a clock signal from the input signals.